An automatic analyzer is a device that causes a chemical reaction by dispensing a sample and a reagent into a cell, measures the absorbance of this mixture, calculates the amount of change in absorbance and/or the rate of change in absorbance based on time series data of absorbance caused by the chemical reaction (hereinafter referred to as reaction process data), and computes the concentration and/or activity of a component of interest in the sample.
Such automatic analyzers are used in biochemical tests, immunological tests, etc., mainly at medical facilities. Results of such tests play an extremely important role when doctors make various diagnoses such as learning about a patient's disease condition, assessing the effects of treatments, catamnestic monitoring, etc. As such, with respect to analyses using automatic analyzers, techniques for guaranteeing that measurements were taken properly are crucial.
As one such method for guaranteeing measurement results, there is abnormality detection using reaction process data. This is a method of guaranteeing measurement results by judging the presence/absence of any abnormal change in absorbance appeared in the reaction process data. Thus, if it is judged that there is an abnormal change in absorbance, it would signify that some abnormality had occurred in the device, sample or reagent at the time of measurement, thereby precluding any guarantee of the measurement results. Consequently, the user would have to stop the analysis, find the cause of the abnormality, and take countermeasures.
As conventional art for such detection of an abnormality in reaction process data, with the “automatic chemical analyzer” disclosed in JP Patent Publication (Kokai) No. 63-101734 A (1988), there is disclosed a technique wherein a photometric time point at which there is a change exceeding a pre-defined threshold is detected with respect to reaction process data for a not-for-measurement wavelength for which absorbance does not vary as a function of the chemical reaction states of a sample and a reagent, and wherein the change in absorbance at the detected photometric time point is corrected with respect to a for-measurement wavelength.